One known example of article transport facilities such as one described above is described in JP Publication of Application No. 2009-12916 (Patent Document 1). The transport device provided to the article transport facility of Patent Document 1 has a travel portion (travel portion 110) which travels in and along a travel path, a first support component (grip portion 150) that can supports an article, and a second support component (movement portion 140) that suspends and supports the first support component. As shown in FIGS. 1 and 2 of Patent Document 1, this transport device is configured to be capable of moving the second support component along a path width direction (lateral width direction of the travel path) with respect to a travel portion, between a retracted position within the travel path and a projected position located to one side of the travel path. And in order to prevent the transport device from tilting due to the shifting of the center of gravity that accompanies the movement of the second support component from the retracted position to the projected position, the transport device of Patent Document 1 is provided with a tilting prevention mechanism (an outrigger 200) which prevents the transport device from tilting by coming into contact with a travel rail (a track 300) from below.